Allows turning on checked mode on a per-isolate basis

runtime/vm/intrinsifier_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 15 matching lines @@
 // The RBX, R10 registers can be destroyed only if there is no slow-path (i.e.,
 // the methods returns true).
 
 #define __ assembler->
 
 
 intptr_t Intrinsifier::ParameterSlotFromSp() { return 0; }
 
 
 void Intrinsifier::ObjectArraySetIndexed(Assembler* assembler) {
-  if (FLAG_enable_type_checks) {
+  if (Isolate::Current()->TypeChecksEnabled()) {
     return;
   }
   __ movq(RDX, Address(RSP, + 1 * kWordSize));  // Value.
   __ movq(RCX, Address(RSP, + 2 * kWordSize));  // Index.
   __ movq(RAX, Address(RSP, + 3 * kWordSize));  // Array.
   Label fall_through;
   __ testq(RCX, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, &fall_through);
   // Range check.
   __ cmpq(RCX, FieldAddress(RAX, Array::length_offset()));
@@ skipping 48 matching lines @@
 
   __ Bind(&fall_through);
 }
 
 
 // Add an element to growable array if it doesn't need to grow, otherwise
 // call into regular code.
 // On stack: growable array (+2), value (+1), return-address (+0).
 void Intrinsifier::GrowableArray_add(Assembler* assembler) {
   // In checked mode we need to check the incoming argument.
-  if (FLAG_enable_type_checks) return;
+  if (Isolate::Current()->TypeChecksEnabled()) return;
   Label fall_through;
   __ movq(RAX, Address(RSP, + 2 * kWordSize));  // Array.
   __ movq(RCX, FieldAddress(RAX, GrowableObjectArray::length_offset()));
   // RCX: length.
   __ movq(RDX, FieldAddress(RAX, GrowableObjectArray::data_offset()));
   // RDX: data.
   // Compare length with capacity.
   __ cmpq(RCX, FieldAddress(RDX, Array::length_offset()));
   __ j(EQUAL, &fall_through);  // Must grow data.
   // len = len + 1;
@@ skipping 1818 matching lines @@
   // Set return value to Isolate::current_tag_.
   __ movq(RAX, Address(RBX, Isolate::current_tag_offset()));
   __ ret();
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64